Resistor material and method of making the same



Patented June 17,1930

UNITED sTA TBS PATENT OFFICE lgmsnnn n. HUNT, or ms'r rirrsnunen, PENNSYLVANIA, Assmnon. 'ro wns'rmo- HOUSE ELECTRIC & MANUFACTURING.

VANIA COMPANY, A conroaanon or :enmzsrn- BESIS'IOB .HATERIALAND METHOD 0! MAKING THE SAME Application filed November This invention relates to resistor materials, more particularl to high-resistance materials and to metho s of manufacturing the same. 4

It is among the objects of this invention to provide a resistor material which shall be simple and economical to manufacture and which may be baked at "a low temperature for a short time to increase the efliciency of the process.

In practising my invention, I provide a resistor material of any suitable type but, preferably, comprising a mixture of a conducting substance, such as lamp-black, conenamel which has a low fusing point and.

ducting oxides or the like, an inert nonconducting material, such \as powdered quartz, clay or any suitable powdered rock,

and a binder consisting of a glass or an which may be soluble or insoluble in the fused state.

Preferably, I employ a mixture of powdered glass 35. parts, powdered quartz 52 parts, clay 10 parts and lamp-black 3 parts. The proportions of ingredients may be varied according to the resistance desired, the mechanical strength and the size and the shape of the article in which it is to be incorporated.

My material may be prepared as follows:

The above-specified ingredients measured in the correct proportions and thoroughly mixed either in the dry state, wherein the materials are ground together and passed through fine-mesh screens a suitable number of times to facilitate mixing, or by a wet process in which the ingreresistor material and extrude it through dies of suitable shape or a mixture, in a fluid state, containing water and a suitable electrolyte, such as carbonate or-silicate of sodium, and cast such fluid mixture into molds of plaster of Paris which absorb the water, thus providing bodies of the desired form.

- oxidizing or a reducing are p -1, 1822. Serial No. 598,420.

bodies are then fired or baked in either an atmosphere. The temperature and time o the properties desired in the finlshed product, but generally the temperature used is between 500? C and 900 C. for a short period of time, varying from five to twentyminutes.

-My process of making resistor material is firing de end upon procedure is a baked article which is I strongly bonded together by means of the low-fusing-temperature flux. 1

I am aware that it has been proposed to provide resistor materials consistin of metallic oxides, clay, quartz and flel spar by making a suitable mixture of said materials, and firing the same at a high temperature, thereby producing a vitreous; non-porous body. My invention differs from the above in that I use a low temperature and complete the baking operation in a comparatively short time, the resultant materialbeing non-vitreous and porous.

My invention has a further advantage in that trial pieces may be made from a mixture and quickly baked and tested, where by the plastic mixture may be modified by the addition of the proper material, if the proportions of ingredientsare found to be incorrect. This reduces the manufacturing losses which have hitherto occurred with materials of this kind. The low temperature and the short time period of baking lower the cost of production and increase the production for a given capacity of furnace, the life of which is increased because of its operation at a temperature which, is not injurious or destructive.

I claim as my invention:

1. A resistor material comprising a silicate glass, quartz, clay and lampblack, partially fused-and bonded together.

2. A resistor material comprising a sili- 40 1 the ingredients together.

parts and lampblack 3 parts.

3. The method of preparing resistor material which comprises providing a mixture of conducting and non-conducting sub'-' stances and a low-temperature fusing glass having a fusion temperature below 900 0., intimately mixing said substances with an inorganic plastic silicate and then firin the same at a temperature below 900 to partially fuse and bind the ingredients together.

4. The method of preparing resistor material which comprises providing a mixture of conducting and non-conducting substances and a low-temperature fusing glass having a fusion temperature below 900 C., intimately mixing said substances with an inorganic plastic silicate and then firing the same at a temperature of. 500 to. 900 C. to partially fuse and bind the ingredients together.

5. The method of preparing resistor material which comprises providmg a mixture of conducting and non-conducting substances and a low-temperature fusing glass having a fusion temperature below 900 0., intimately mixing said substances with an inorganic plastic silicate and then firing the same at a temperature of 500 to 900 C. for a sufiicient length of time to artially fuse-and bind the ingredients toget er.

6. A method of preparing resistor ma- .terial which comprises providing a mixture of conducting and non-conducting substances, a plastic clay and a silicate glass that fuses at a temperature-below 900 C. and firin the same at a temperature below 900 C. or a time period of from five to twenty minutes, to partically fuse, and bind 7 A method of preparin resistor material which comprises provi 'ng a mixture of conducting and non-conducting sub stances, a plastic clay and a silicate glass that fuses at a low-temperature and firing the same at a temperature of 500 C. to 900 C. for a period of between five and twenty minutes, to partially fuse and bind the ingredients together.

8. A method of pre aring resistor material which comprises forming a mixture of 'a silicate glass, quartz, clay and lampblack and firing the same at 500 to 900 C.

9. A method of preparing resistor material which comprises forming a mixture of glass, quartz clay and lampblack and firing the same at a temperature of 500 C. to 900 C. for a period of between fiveand twenty minutes.

10. A resistor material comprising a fluxing glass having a fusion temperature below 900 G., quartz, clay and lampblack,

fused and bound together at a temperature of 500 to 900 C.

11. A resistor material comprising quartz and lampblack in the proportions of about 14 parts quartz, one art lampblack, sufii 'cient cla so thatthe mixture may be readily mol ed, and a sufiicient quantity of a fluxing glass having a fusion temperature below 900 C. so that the mixture maybe giged at a temperature of between 500 and 12. A method of preparing resistor m'aa conducting and'non-conducting substance,

a plastic clay and a silicate glass that fuses at a temperature below 900 C. thoroughly together, forming the mass into the shape of a resistor, drying the'formed body at a temperature of about 150 C. and then firing the dried body at a temperature bet-ween 500 and 900 C.

In testimony whereof, I have hereunto subscribed my name this 27th day of October, 1922.

MARSDEN H. HUNT.

III 

